結果
問題 | No.1300 Sum of Inversions |
ユーザー |
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提出日時 | 2020-12-02 22:11:21 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 545 ms / 2,000 ms |
コード長 | 4,475 bytes |
コンパイル時間 | 3,232 ms |
コンパイル使用メモリ | 213,092 KB |
最終ジャッジ日時 | 2025-01-16 13:36:56 |
ジャッジサーバーID (参考情報) |
judge5 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 34 |
ソースコード
#include <bits/stdc++.h>using namespace std;using ll = long long;template <class T> using vec = vector<T>;template <class T> using vvec = vector<vec<T>>;template<class T> bool chmin(T& a,T b){if(a>b) {a = b; return true;} return false;}template<class T> bool chmax(T& a,T b){if(a<b) {a = b; return true;} return false;}#define rep(i,n) for(int i=0;i<(n);i++)#define drep(i,n) for(int i=(n)-1;i>=0;i--)#define all(x) (x).begin(),(x).end()#define debug(x) cerr << #x << " = " << (x) << endl;constexpr ll mod = 998244353;struct mint {ll x;mint(ll x=0):x((x%mod+mod)%mod){}friend ostream &operator<<(ostream& os,const mint& a){return os << a.x;}friend istream &operator>>(istream& is,mint& a){ll t;is >> t;a = mint(t);return (is);}mint& operator+=(const mint a) {if ((x += a.x) >= mod) x -= mod;return *this;}mint& operator-=(const mint a) {if ((x += mod-a.x) >= mod) x -= mod;return *this;}mint& operator*=(const mint a) {(x *= a.x) %= mod;return *this;}mint operator+(const mint a) const {mint res(*this);return res+=a;}mint operator-(const mint a) const {mint res(*this);return res-=a;}mint operator*(const mint a) const {mint res(*this);return res*=a;}mint pow(ll t) const {if (!t) return 1;mint a = pow(t>>1);a *= a;if (t&1) a *= *this;return a;}// for prime modmint inv() const {return pow(mod-2);}mint& operator/=(const mint a) {return (*this) *= a.inv();}mint operator/(const mint a) const {mint res(*this);return res/=a;}bool operator==(const mint a)const{return x==a.x;}};template<typename Monoid,typename F>class SegmentTree{private:int sz;vector<Monoid> seg;const F op;const Monoid e;public:SegmentTree(int n,const F op,const Monoid &e):op(op),e(e){sz = 1;while(sz<=n) sz <<= 1;seg.assign(2*sz,e);}void set(int k, const Monoid &x){seg[k+sz] = x;}void build(){for(int i=sz-1;i>0;i--){seg[i] = op(seg[2*i],seg[2*i+1]);}}void update(int k,const Monoid &x){k += sz;seg[k] += x;while(k>>=1){seg[k] = op(seg[2*k],seg[2*k+1]);}}Monoid query(int l,int r){Monoid L = e,R = e;for(l+=sz,r+=sz;l<r;l>>=1,r>>=1){if(l&1) L = op(L,seg[l++]);if(r&1) R = op(seg[--r],R);}return op(L,R);}Monoid operator[](const int &k)const{return seg[k+sz];}};template<class T>class Compress {int N;map<int,T> value;vec<T> v;vec<T> cmp;public:Compress(){}void add(T x){v.push_back(x);}void build(){for(auto &x:v) cmp.push_back(x);sort(cmp.begin(),cmp.end());cmp.erase(unique(cmp.begin(),cmp.end()),cmp.end());N = cmp.size();}int id(T val) {return lower_bound(cmp.begin(),cmp.end(),val)-cmp.begin();}T val(int id) {return cmp[id];}int size(){return N;}};int main(){cin.tie(0);ios::sync_with_stdio(false);int N;cin >> N;vec<int> A(N);Compress<int> cmp;rep(i,N){cin >> A[i];cmp.add(A[i]);}cmp.build();int M = cmp.size();auto op = [](mint a,mint b){return a+b;};SegmentTree<mint,decltype(op)> seg(M,op,(mint) 0);vec<SegmentTree<mint,decltype(op)>> L;vec<SegmentTree<mint,decltype(op)>> R;rep(i,3){L.push_back(seg);R.push_back(seg);}mint ans = 0;rep(i,N){int id = cmp.id(A[i]);ans += L[1].query(id+1,M)*A[i];drep(j,3){if(j) L[j].update(id,L[j-1].query(id+1,M));else L[j].update(id,1);}}drep(i,N){int id = cmp.id(A[i]);ans += R[1].query(0,id)*A[i];drep(j,3){if(j) R[j].update(id,R[j-1].query(0,id));else R[j].update(id,1);}}rep(i,M) L[0].set(i,0);L[0].build();rep(i,N){int id = cmp.id(A[i]);ans += L[0].query(id+1,M)*R[0].query(0,id)*A[i];L[0].update(id,1);R[0].update(id,-1);}cout << ans << "\n";}